Specification for SEMI Equipment Communications Standard 1 Message Transfer (SECS-I)

The SEMI E4 standard defines a serial communication via RS-232. Although it was initially developed for host-to-equipment communication, it is often used within the tool communication: equipment control software communicates with individual hardware components using their SECS-I interface. While this standard describes the connection and transaction procedures as well as how handle communication failures. After this connection is set up, it is possible to exchange SECS-II messages. The structure and content of these messages are described in SEMI E5 (SECS-II).